Synchronize on threads on wait/notify

[kaka/cakelight.git] / src / kaka / cakelight / mode / VideoMode.java

package kaka.cakelight.mode;

import kaka.cakelight.Configuration;
import kaka.cakelight.FrameGrabber;
import kaka.cakelight.VideoDeviceListener;
import kaka.cakelight.VideoFrame;

import java.io.File;
import java.io.IOException;
import java.util.Optional;
import java.util.function.Consumer;

public class VideoMode extends Mode {
    private Configuration config;
    private Thread grabberThread;
    private Consumer<VideoFrame> frameConsumer;
    private VideoDeviceListener deviceListener;
    private boolean isPaused = false;

    public VideoMode() {
        deviceListener = new VideoDeviceListener();
        deviceListener.onVideoDeviceChange(this::onVideoDeviceChange);
    }

    @Override
    public void enter(Configuration config) {
        this.config = config;
        deviceListener.startListening();
    }

    @Override
    public void pause() {
        isPaused = true;
    }

    @Override
    public void resume() {
        isPaused = false;
	synchronized (grabberThread) {
	    grabberThread.notify();
	}
    }

    @Override
    public void exit() {
        grabberThread.interrupt();
        deviceListener.stopListening();
    }

    private void startGrabberThread(File videoDevice) {
        assert frameConsumer != null;
        grabberThread = new Thread() {
            public void run() {
                try (FrameGrabber grabber = FrameGrabber.from(videoDevice, config)) {
                    while (!isInterrupted()) {
                        Optional<VideoFrame> frame = grabber.grabFrame();
                        if (isPaused) {
			    synchronized (grabberThread) {
				wait();
			    }
                        }
                        if (frameConsumer != null) frame.ifPresent(frameConsumer);
                        frame.ifPresent(VideoMode.this::onVideoFrame);
//                        timeIt("frame", grabber::grabFrame);
                    }
                } catch (IOException | InterruptedException e) {
                    e.printStackTrace();
                }
            }
        };
        grabberThread.start();
    }

    public void onVideoFrame(Consumer<VideoFrame> consumer) {
        frameConsumer = consumer;
    }

    private void onVideoFrame(VideoFrame frame) {
        updateWithFrame(frame.getLedFrame());
    }

    public void onVideoDeviceChange(Optional<File> videoDevice) {
        // Should only happen when this mode is active!
        if (grabberThread != null) {
            grabberThread.interrupt();
        }
        videoDevice.ifPresent(this::startGrabberThread);
    }
}